The invention relates to a safety device on metal-forming machines, in particular on pneumatic press machines where short-stroke press operations are performed, for preventing intervention in a danger area during a working motion of a tool and for preventing unintentional closing motions when using workpieces. The machine includes a machine housing, a power-generating device, a control and a tool arrangement having a fixed part and a movable part and the actual metal-forming tool connected thereto.
The EC machine guideline stipulates which rules and standards are to be observed in order to achieve safety at work to the greatest possible extent, for example on press machines. Accordingly, hand protection can be achieved in particular by only safe tools being used, by the danger point being shielded and by two-hand controls or contactless protective devices, e.g. light barriers, being used.
Such safety devices are known in a multiplicity of embodiments and are accurately matched to the respective conditions of use. However, it has been found that these safety devices cannot always be used or can only be used with a certain residual risk.
Thus, for example in the manufacture of plug-in connectors fitted with cables, i.e. during the securing of cables in plug-in connectors, it is conventional practice to connect the outer and/or inner conductors to one another by a crimping operation. A crimping tool, which can be operated by hand and therefore involves little risk of injury, is useful for this in the case of smaller cable cross sections. Nonetheless, crimping by hand is harmful, especially when this operation has to be repeated continually.
Pneumatic presses are therefore also used for the connecting of electric cables or lines having a relatively small cross section in order to make the work easier for the assembly workers.
Known safety devices with two-hand control cannot be used here, since, to produce the connections, both hands are required even during the press operation in order to hold the connecting elements in position. That is to say, the operator of such a press, before the friction grip is produced and while the friction grip is being produced, must hold the parts of the plug-in connector in position with one hand and the inserted cable with the other hand, since otherwise the electrical and also the mechanical connection between cable and connector will be effected in such a way that it is either faulty or damaged. At worst, terminal parts may be destroyed.
Electric and electronic safety devices are often susceptible to faults and do not always provide onehundred per cent safety.